Lifting mechanism for industrial truck



April 1961 B. 1. ULINSKI 2,980,271

LIFTING MECHANISM FOR INDUSTRIAL TRUCK Filed Feb. 11, 1957 3 Sheets-Sheet 1 INVENTOR. B. I. UL/NSK/ April 18, 1961 B. 1. ULINSKI 2,980,271 LIFTING MECHANISM FOR INDUSTRIAL TRUCK Filed Feb. 11, 1957 3 Sheets-Sheet 2 IN V EN TOR. B (/L/Nok/ Array/var April 1961 B. 1. ULINSKI 2,980,271

LIFTING MECHANISM FOR INDUSTRIAL TRUCK Filed Feb. 11, 1957 3 Sheets-Sheet 3 TEL. E-

IN V EN TOR. 5. 1 U2 lA/Gk/ BY rray/v5) United States Patent LIFTING MECHANISM FOR INDUSTRIAL TRUCK Bronislaus I. Ulins'ki, Flossmoor, Ill., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Filed Feb. 11, 1957, Ser. No. 639,367

9 Claims. (Cl. 214-140) load lifting platform or forks for movement on channeled uprights. In this way, the load is elevated through movement on the uprights, while the load can be tilted through tilting movement of the uprights so as to facilitate taking the load off the truck, or to move the load with the truck.

wardly so as to stabilize the truck and also to stabilize the load on the truck. v

It has been proposed that a load platform or other load lifting member be actuated through operation of a lever system. The purpose of a construction of this class is to locate the load lifting mechanism on the truck in a position where it will act to counterbalance the load carried by the platform or the forks. Further, it has been proposed that in a leverage system of the class described, the forks or other load platform move vertically so as to facilitate the handling of a load as it is being stacked or placed in storage. By moving the load vertically in a single plane, the same results are accomplished as I have now conceived a construction through which I am able to lift aload platformor lifting forks so that the platform or forks move substantially in a particular vertical plane. At the samewtime, I am able through the particular manipulationof fthe lifting means, to effect tilting ofthe load'platform or forks in any lifted posltion thereof.

, As a feature of my invention, I form the load lifting .25 For example, it is frequently desired to tilt the load backstructure, such as forks or the like, as part of a parallelogram and then I arrange to swing this parallelogram so that the load moves substantially vertically at all times. This swinging movement is made possible simply by holding in a particular plane that portion of the parallelo gram that is opposite; the load platform or forks in-the parallelogram system; As a further particularfeature of the invention, the parallelogram member that is held in a particular position is adapted to be rotatedin any position of the parallelogram; thereby pivoting the forks rearward ly. so asio .tilt the'load. Moreover, the load may be Eeleyatedorlowered while. in tilt ed position. I

when the load platform or forks are moved on vertical As a further particular feature of the invention, the parallelogram member that controls the positioning of the forks is itself a part of a further parallelogram system in which its opposed parallelogram member is controlled by a hydraulic ram or other positioning device. Through this hydraulic ram the parallelogram member may then move that part of the parallelogram leverage system that lifts the load so as to tilt the load in all positions thereof.

This novel concept contributes an exceedingly simple and effective construction that makes possible the utilization of a leverage system for lifting a load platform or forks and for moving the load as effectively as though the load were mounted for movement on the usual channeled uprights. Moreover, since I do not utilize uprights, I enable the operator to have much better vision for driving the truck or for manipulatingthe load. I believe, therefore, that my truck construction yields all the advantages of a leverage lifting system together with all the further advantages of an upright channel system.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may 'be better understood, and in order that my contribution tothe art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. I'hose skilled in the art'will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spiritand scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.

In thedrawings:

Fig. 1 is aside view showing an industrial truck that utilizes my novel lifting mechanism. 1 a

Fig.2 is like Fig. l but illustrates the lifting movements of my mechanism. a a

Fig. 3 illustrates the tilting movement of the load carrier. v 1

Fig. 4 shows a plan view of my invention. ,1

Fig. 5 is a diagrammatic view showing the parts of the lifting mechanism in the positionof Fig. 1.

Fig. 6 shows the same parts in the dotted position of Fig. 2. V I

Fig. 7 shows the parts in the full line-position of Fig. 2, and 7 a a Fig. 8 shows the parts in the position of Fig. 3.

Referring now more particularly to the drawings, I show invention utilized to mount a load' carrier 10 for lifting movement relatively to an industrial truck T. I have chosen to show the load carrier 10 constructed with a front plate 11 that is somewhat like the front plate used on aconventional load lifting carriage,[and that is adapted to accept load forks 12.- It is to be understood,

however, that the "particular construction of thefload carrier it? is not important to an understanding off my invention, audit is necessary to r'ealizemerely that the carrier it is adapted'to support a load that is to be handled. The truck T has amain frame 13 with steering and driving wheels 14, 15, and has also a sea-r16 .for

the operator controls 17 through which the operator will swing vertically certain longitudinal I fti'ally a particular plane. 7 K

'the swing links 27,-28 in'such away that the'fplane in rearward direction, tr line-A in- Fig; 2.

"tia'lly in one plane,

' 73 3 acts against, the lower-arm 21, or'against link"27. Of

is fs zlt a n in i1 and f h link as en sa a ram .J f :1 ii j A I control that'seco'nd parallelogram'throughua hydraulic; 7

controls the truck and lifting mechanism, as will be un derstood by those skilled in the art.

In the extremely novel lifting mechanism that I con 20, 21, well shown in Figs. 1. to 3., Those arms 20, 21 are pivoted at their forward ends to the load carrier through pivots 22, 23 that are vertically spaced, while the rearward ends of arms 20, 21 are attached to a lever 24 through-pivotsgZS, 26 that have the same spacing as do'that pivots 1'22, 23. Actually, I utilize corresponding parallel arms: at opposed sides of the truck, those on the left-hand, side being indicated in Fig. 4 by the numerals a, Mag -However; since J the truck I through first and second swing links 27 1Lt8. Thus, one end of the first swing link-27 is'pivoted to a medial portion of the arm 21 through a pivot '29, While the opposed end of that link 27 rotates on a pivot on a an upper portion 3110f truck frame 13. Opposed ends of the second swing link 28 are pivoted 'tofthe rear end of i '7 1arm21-through the pivot 26, and to truck frame 13 :throughapiv'ot 372. i

The arrangement is such that the parallel arms 20, 2 1 on'the links '27, 28 while having a movement relatively to the truck T.r "Thus, when'the arms 20, 21 swing to lift the'load'carri'er 1" 10'fro'mthet'lowered position shown'in Figs. 1 and 5,

the links 27, 28 will cause the arms and carrier to move also (in a rearward direction, toward the position shown in dottedllinesfin'Eig. 2, and also shown in Fig. 6.' 7 When vswinging further to arfull elevated position, the arms 20, 21am tcar'rier 10 will move somewhat in a forward direction whereby to lie in the full line position shown in Fig; '2 and in Fig.7. I thereby enable the arms 20,121 to lift the load carrier 10 with the carrier moving in substan- Actually, I prefer to construct which the load carrier 10-moves is inclined slightly ina as is indicated 'by "the dot anddash With the carrier 10 movingsubstan- I am able to .lift andto carryja load in the same jwayjas in a lift truck that utilizes conventional uprights.'r"

To impart lifting movement to the parallel arms 21 ilprefer to utilize' a'hydraulic ram 33, that ram being pivoted to the truck frame 13 through a ipivot-34,' and 7 acting at its upper end against the pivot 29 on'themedial portion of ar'mf21; Itmjay be said in effect thatrarn' Y coursefit isfconceivable that the ram'33may be arranged ,to' actjat: substantially anyrpoint, on jthe arm Zl or link 27.

' I shall now describe that part" of my invention that enables the load carrier'ltl to be'tilted when that is de siredr 'by the operatonofithe truckr; I'shallfirst call attention 7 'Qt'othe fact that Leq'ui'p tlie'lever 24with a further'pivot 35,-that pivot in mypreferredconstructionbeing offset 7 I jwhereby the lever 24 is, in effeot, a twoearmedlever; Fur- 1 then, I utilize a link'36 that extends between thepivot "jand'apivot 37 on a link 38; The-link 38 mounted'to r ts. bn'thet ucls ame 3 through h m pii fi i utilized for the swing linklgsgand fgrms Withither *ramss thatja ctslagainst the linkf38, thus' enabling me to 9 positiono f link-3a,; Since limg ssf'is 5 One position is shown for example in Figs. 1, 2, 5 and 7.

By rotating link 38 through ram 39 'I can tilt the load car- 7 rier, as shown in Figs. 3 and 8. Actually, my invention enables me to effect tilting of the load carrier 19 in all positions to which the carrier moves in its vertical plane of lifting movement. Moreover, the lift ram 33 will be effective to move the load carrier 10 vertically whether or not the carrier is' titltedr Because I can tilt the load carrier, those persons skilled 'in' the art willappreciate that I facilitate thefhandli ngfo'f 'aload and the stabilizing the parts of my mechanism are alike at bothsides of the 15 'of the load relatively tothe' truck. a a truck, I believe it will suthce if I describe merely the right: I have already referred v to, the factvthat l arrange the hand side; shown in Figs; 1,2 and 3. f p 7 i partsof-my novelllifting mechanism atlopposed sides'of 1n order .to understand the movements of the parallelothe truck. Thusgit will be :seen whilecons'idering Fig. 4 grain that includes the arms-'20,. 21, 1itisneces'sary first marine lifting arms 20, 21 and 20a and 21a extend at V ,to' realize that '1 swing the parallelogram relatively to '20 opposed'sides of the'truck controls 17 and operators seat 25' thetruck'orwhen manipulating'the load carrier- 10.

I believe thatrthe construction and ioperationrtof my extremely novel load lifting mechanism will:now be fully understoodf Through my'novellconcepgit 'ispossible to achieve all-the advantages of a leverage lifting system, together with the advantages of a channel upright system. "Thusfl am able not only to hold the load'carrier in a particular plane during its lifting movementgbutalso to achieve tilting ,of the load {carrierrin all positions thereof.

These things- I accomplish without, truck uprights, yet 35 ilrdoinotrequirein my leversy stem means that are complicated and difficult 'tooperatej Actually; my novel liftingmechanism is quite simple, despitethe fact that it will enable an industrial truck to handle a] load with exeeedingly good effect. j I believejthat those skilled in theiart will nowappre'ciate the veryiconsiderable value of-myiinvention, .f i J a fiIgnow claimr a I 1. In atruck of'the class described, a load carrier, 'upper and lower parallel arms each pivoted at one end thereof toisaid'load carrier in predetermined spaced relation,l-said :arm's being each pivoted at theirppposed ends to 'a-leverjin the same predetermined spaced "relation "'Lwhereby to form" a first parallelogramfcomprising said 7 arms','s 'aid load carrier and said lever, a 'swinglink pivoted at one end tonne of said arms'and; atjits other endto the truck,asecond-:swing link pivoted at one end to said lever I I on-the's'ame axis as the pivot'of-saidlower arm and at its particulate angular position predetermined J by Said second iis a lsl a smw la upp s dt. r t* ar lc m Ifor "swinging movern'ent' us for swinging said first V parallelograrnfon saidswin links wher'eby,tojraise that I parallelogram relatively to i the itruck and to elevate the through movement oftheiseond' parallelogram forrotating said leverrelatively-to'Saidsecond' swing, link whereby totchang'egthe' angularposi n of s'aid loadfcarrier Q in all elevated positions nthereo I 25In .atruck" of the: class.

upper s and, lower parallel arms thereof to said "load carrier in p b toij rm an a lqaram s mpr s n cs d Latin 5 said loadearrier and 'said lever} a pivoted other end: to the truck; itwo additional linke pivoted to :saidf'lever and seeond swinglink and, forming-therewith a second parallelogram :ffor positiohingsaid;lever. in a described V n tlsim b s asfifn iw ii tii i md s p 10 a lever the samel predetermined' spaced 'relation at one end to one of said arms and at its other end to the truck, a pair of swing links each pivoted at one end to said lever with one of said links pivoted to the lever on the same axis as the pivot of said.lower parallel arm, the opposed ends of said pair of swing links being pivoted relatively to the truck, and means for swinging the parallelogram relatively to the truck on said pair of swing links with said first swing link guiding the movement of said parallelogram and its load carrie 1 3. In a truck of the class described, a load carrier, upper and lower parallel arms each pivoted at one end thereof to said load carrier in predetermined spaced relation, said arms being each pivoted at their opposed ends to a lever in the same predetermined spaced relation whereby to form a first parallelogram comprising said arms, said load carrier and said lever, a swing link pivoted at one end to one of said arms and at its other end to the truck, a second swing link pivoted at one end to said lever and at its other end to the truck, two additional links pivoted to said lever and second link and forming therewith a second parallelogram for positioning said lever in a particular angular position predetermined by said second parallelogram, means for swinging said first parallelogram vertically on said swing links whereby to elevate the load carrier in a particular plane relatively to the truck, said lever eifective by its predetermined angular position to hold the parts of the first parallelogram during said swinging thereof so as to maintain the load carrier in a particular angular position, and means effective through the second parallelogram for rotating said lever relatively to said second swing link whereby to change the angular position of said load carrier in any position to which it is elevated in said particular plane.

4. In a truck of the class described, a load carrier, a pair of arms pivoted at one end to said load carrier in predetermined spaced relation, said arms being pivoted at their opposed ends to a lever in the same predetermined spaced relation whereby to form a parallelogram comprising said arms, said load carrier and said lever, a second parallelogram including said lever and a pair of parallel links pivoted to said lever, means for swinging the first parallelogram bodily on said parallel links relatively to the truck, a guide link pivoted at one end to an arm of the first parallelogram and at its otherend to the truck for controlling the bodily movement of said first parallelogram on said pair of parallel links, and means acting through said pair of parallel links to control the angularity of said lever whereby to control the angular position of the load carrier relatively to the truck.

5. In a truck of the class described, a load carrier, parallelogram links pivoted at one end thereof to said load carrier, further links pivoting the opposed end of said parallelogram links to the truck and acting through the parallelogram links to control the angular position of the carrier, an intermediate link pivoted to the truck and to a point intermediate the ends of one of said parallelogram links, means for swinging said parallelogram links on said further and intermediate links whereby to lift said carrier relatively to the truck, and said intermediate link acting during the lifting movement to move bodily the parallelogram links whereby to hold said load carrier in a predetermined path. I

6. In a truck of the class described, a load carrier, a pair of arms each pivoted at one 'end thereof to said load whereby to efiect the lifting and lowering of said load carrier in predetermined spaced relation, said arms being load carrier may be adjusted.

carrier, said control link guiding said arms so that the load carrier moves in substantially a vertical plane with said arms swinging bodily with said lever on said vertical links as said load carrier swings on said arms relatively to said lever, and a second ram for changing the angular alignment of said lever relatively to said vertical links whereby to change also the vertical alignment of said carrier in all elevated positions thereof and during its elevating and lowering movements.

7. In a truck of the class described, a load carrier, a pair of arms pivoted at one end thereof to said load carrier in predetermined spaced relation, said arms being pivoted at their opposed ends to a lever in the same predetermined spaced relation whereby to form a parallelogram comprising said arms, said load carrier and said lever, a pair of vertical links pivoted at their upper ends to said lever and at their lower ends relatively to said truck and mounting said lever and thereby said parallelogram for swinging movement relatively to said truck, a ram extending between said truck and said arms for swinging said arms and load carrier relatively to said lever, a control link pivoted at one end to a fixed portion of said truck and at its other end to one of said arms whereby to control the position of said load carrier to hold it always substantially in the same vertical plane through the swinging of said parallelogram of arms, load carrier and lever bodily with said lever on said vertical links, and a second ram for changing the angular alignment of said lever relatively to said vertical links whereby to change also the vertical alignment of said load carrier in all elevated positions thereof and during its elevating or lowering movement.

8. In a truck of the class described, a load carrier, a pair of relatively long arms pivoted at one end thereof to said carrier in predetermined spaced relation, said arms being pivoted at their opposed ends to a lever in the same predetermined spaced relation whereby to form a parallelogram comprising said arms, said load carrier and said lever, means for swinging said arms vertically about their pivots on said lever between a position in which said load carrier is substantially above said pivots and a position in which said load carrier is substantially below said pivots,

movable means mounting said lever on said truck forlongitudinal movement relatively to said truck while maintaining said lever in a particular angular position relatively to said truck during vertical swinging movement of said arms whereby said load carrier may move in a substantially vertical path relatively to said truck, means operatively interconnecting said lever and arms and a portion of said truck for eiiecting automatically said longitudinal movement of said lever during swinging movement of said arms whereby to restrict bodily movement of said load carrier to said vertical path, and means for selectively effecting angular movement of said lever relatively to said truck and for holding said lever in a particular angular position during swinging movement of said arms whereby the angular position'of the 9. In a truck of the class described, a load carrier, a pair of relatively long arms pivoted at one end thereof to said load carrier in predetermined spaced relation,

said'arms being pivoted at their opposed ends to a lever in the same predetermined spaced relation whereby to form a parallelogram comprising said arms, said load carrier and said lever, means for swinging said arms vertically about their pivots on said lever between a position in which said load carrier is substantially above said pivots and a position in which said carrier is substantially below'said pivots, a pair of vertical links of a length substantially less than one-half the length of said arms pivoted at their upper ends to said lever and pivoted at their lower ends relatively to said truck so that said lever and arms may move longitudinally of said truck by swinging movement of said links to offset longitudinal move: ment of said load carrier relatively to said truck during 'c 'rrior may m v Epsom 1- vertical swinging movement the re of whereby said load U in a substantially vertical path relai sflys 1. 11' 9} m s oparatiyely- =in 9 ti g said lever and arms and a portion of said fruk foifioiby 'to restrictbodily mo vemorit of, said load cargie go said vertical path, means for imparting'angmapmoveme'nt to said lever rclativoly to said 11115111 11 said truck,

and moans for selqctivoly' efiooting said angular movement of said lgvepagd for holding said igvfipin a par:

ticular angular position during swinging mgvomant, of V 7 said arms whereby the angular position of tho-,loadcaxrier may be adju'stod;

, 111g 'ali tomatically said longitudinal movemont f said lever, and arms during swinging mgvcn e nt fsaid' arms where'- 

